|Values are valid only on day of printing.|
Diagnosis, carrier detection, and determination of genotype of galactose-1-phosphate uridyltransferase deficiency, the most common cause of galactosemia
Differentiating Duarte variant galactosemia from classic galactosemia
Confirming results of newborn screening programs
Preferred test to evaluate for possible diagnosis of galactosemia, routine carrier screening, and follow-up of abnormal newborn screening results. Comprehensive reflex test begins with quantitative galactose-1-phosphate uridyltransferase (GALT) enzyme analysis (GALT / Galactose-1-Phosphate Uridyltransferase [GALT], Blood). If quantitative GALT enzyme value is consistent with a diagnosis of or carrier status for galactosemia, DNA analysis of the GALT gene (GAL14 / Galactosemia Gene Analysis [14-Mutation Panel]) is performed to detect 14 galactosemia alleles : -119_-116delGTCA, D98N, S135L, T138M, M142K, F171S, Q188R, L195P, Y209C, K285N, N314D, Q344K, c.253-2A>G, and 5 kb deletion.
Galactose-1-phosphate uridyltransferase (GALT) deficiency is the most common cause of galactosemia and requires lifelong restriction of dietary galactose.
This is the preferred test to evaluate for possible diagnosis of galactosemia, routine carrier screening, and follow-up of abnormal newborn screening results.
Test includes both quantitative GALT enzyme analysis (GALT / Galactose-1-Phosphate Uridyltransferase [GALT], Blood) and in patients with decreased enzyme activity, reflex to DNA analysis of the GALT gene (GAL6 / Galactosemia Gene Analysis [6-Mutation Panel]).
For monitoring of dietary compliance, see GAL1P / Galactose-1-Phosphate (Gal-1-P), Erythrocytes.
|Test ID||Reporting Name||Available Separately||Always Performed|
|GAL14||Galactosemia Gene Analysis||Yes||No|
Testing begins with galactose-1-phosphate uridyltransferase (GALT) enzyme analysis. If GALT is > or =24.5 nmol/h/mg of hemoglobin, testing is complete. No molecular test will be performed. If GALT is <24.5 nmol/h/mg of hemoglobin, GAL14 / Galactosemia Gene Analysis (14-Mutation Panel) will be performed at an additional charge.
See Galactosemia Testing Algorithm in Special Instructions.
Enzyme Reaction Followed by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)